Draft gear



May 2 2, 1928.

1,670,335- H. BARNARD DRAFT GEAR Filed' April 16, 1926 Patented May 22, 1928.

UNITED STATES PATENT OFFICE.

ma BABNABD, or cmoaeo, ILLINOIS, Assrenon TO UNION DRAFT GEAR (20., or cmoaeo, rumors, A CORPORATION or DELAWARE.

DRAFT GEAR.

The invention relates to draft gears comprising a pair of nested sprin s having seats in common, and more speci cally to draft gears of the type disclosed in the patent to James R. Cardwell, No. 1,275,527, of August 13, 1918.

The object of the invention is to provide for the use of s rings which in service position willbe of unequal length, the nner spring being the longer.

The invention consists of a structure such as is hereinafter described, and as illustrated in the accompanying drawin s, in which Fig. 1 is a detail plan of t e gear, partly in section, as applied to the car framing; and

Fig. 2 is a detail section on the line 2-2 of Fig. 1.

There is shown a pair of center or draftsills 10, and a draft rigging 11, of the Cardwell type.

The draft gear comprises a pair of followers 12, 13, seated against suitable stops, such as the cross-bars 14, 15, which are slidable in slots 16, 17, in the sills; an'd a plurality of wedge elements of any preferred form are shown as consisting of two pairs of triangular wedge-blocks 18, 19, seated, respectlvely, against the two followers, a central wedging element 20 interposed between the triangular blocks of each pair, and a pair of wedge shoes 21, 22, cooperating with the outer faces of the triangular blocks of each pair; a tension rod 23 extending transversely through the central wedging element and the two shoes, and also through the sills 10. Upon the rod 23 there is slidingly sleeved a pair of spring seats, as 24, and a pair of opposed spring seats, as 25, having their faces annularly channeled, as shown at 28, are adjustably fixed upon the outer ends of the rod. A pair of nested springs 26, 27, react between the inner and outer spring seats, the practice being to e1nploy springs of commercial form and of equal length.

Upon the compression of a gear of this type the shoes, as 22, are forced laterally outward against the resistance of the nested springs.

When the gear is assembled the springs are placed under some degree of compression, and inasmuch as the distance between the bottom of the groove 28 and the face of the seat 24 is somewhat greater than the distance between the outer portions of the two seats it follows that in service position the inner spring is slightly longer than the outer spring, and this differentiation continues, whatever may be the degree to which compression is carried. Normally, the compression of the gear is limited by the engagement of longitudinally moving elements, as by 13, with the ends of the element 20. It frequently happens, however, in service that the springs are too greatly compressed by setting up the spring seats, as 25. resulting in complete compression of the springs be fore movement of the gear is stopped in the intended manner.

Under such circumstances, the gear movements have been limited by the complete compression of the springs and the shocks have been delivered to the shoes as 22 and to the spring seats as 25. These shocks being deliveredto the middle portion of the shoes, they are frequently broken, thus entailing ver considerable expense, particularly for labor in replacing the broken parts.

By the introduction of the channel 28, the complete compression of the inner spring never occurs, andunder the action last described, the shocks of complete compression of the gear are communicated to the outer portions only of the spring seats, and as these seats are made of malleable iron, they yield suflicient-ly to save from destruction the shoes, which are of gray iron. If the seats are broken or so greatly distorted as to impair their usefulness, they may be readily replacedwithout bling the gear or other parts thereof.

While a simple and preferred form of construction is disclosed, it is obvious that various changes of detail may be made within its scope.

I claim as my invention In a draft gear, in combination, a laterally movable tension rod having spring seats ateach end, a pair of shoes slidably mountthe contact of the followers 12,.

disassemed on the rod,a pair of nested springs of 

